Golden, Colo., July 6, 1998 Two new studies highlight the benefits of biodiesel in reducing overall air pollution and in helping to reduce the United States' dependence on imported oil.
The U.S. Department of Energy's National Renewable Energy Laboratory (NREL) conducted both studies: An Overview of Biodiesel and Petroleum Diesel Life Cycles and Biodiesel Research Progress, 1992-1997.
Biodiesel is a renewable diesel fuel made by chemically combining a natural oil or fat with an alcohol, such as methanol or ethanol. In the United States, soybean oil is currently the preferred primary feedstock. Biodiesel can be used in any conventional diesel engine and distributed through existing industry infrastructure.
"Biodiesel is the perfect substitute for petroleum diesel. You don't need special pumps or high pressure equipment and you don't need to buy new bus engines," NREL's Biodiesel Project Manager Shaine Tyson, said.
The first study is a life cycle "cradle to grave" comparison of biodiesel and petroleum diesel. Life cycle means looking at the whole picture of how the fuels are made, from the extraction of raw materials to make petroleum or grow soybeans, to the fuels' use in an urban bus.
The study concludes that the use of neat biodiesel (100 percent biodiesel) reduces carbon dioxide emissions by more than 75 percent over petroleum diesel. Using a blend of 20 percent biodiesel reduces carbon dioxide emissions by 15 percent.
Scientists believe carbon dioxide is one of the main greenhouse gases contributing to global warming. Biodiesel also produces less particulate, carbon monoxide and sulfur dioxide emissions, all targeted as public health risks by the Environmental Protection Agency.
The NREL study concludes that since biodiesel can be used in conventional diesel engines, the alternative fuel can directly replace petroleum products, reducing the country's dependence on imported oil.
Tyson said several obstacles to biodiesel's widespread use still must be overcome. Biodiesel is more expensive than petroleum diesel. Although biodiesel overall is a cleaner burning fuel, it produces slighter higher amounts of the pollutant nitrogen oxide.
NREL's second new report, Biodiesel Research Progress, is a compendium and summary of most biodiesel research projects conducted in the U.S. by both government and private industry in the past five years.
Both reports can be ordered from NREL's Document Distribution Service, E-mail address, email@example.com; telephone 303-275-4363, or by mail, 1617 Cole Blvd., Golden, CO, 80401.
Visit NREL on line at www.nrel.gov